I make a lot of very simple little quilts for the local hospital. They are single piece of interesting fabric for top, batting, backing, quilted vertically about every 4.5" and do binding by hand. when I have a mental block I start putting these together. First step is layering and pinning, second step is quilting and third is binding.l
I do this and not waste time worrying about "the next project". In almost all cases an idea will come to me while doing this.
I will also put some groups of fabric in plain sight as I work on other things and again, ideas will start coming.
An example of an unintended project. My sister sent me two of her "quilty" dresses. One had never been worn the other had been made from a primitive line of fabric back in the 90's. I was going to give them to the quilt guild for their sale table. I did give the new one to them. I kept the one my sister had made. It was a tiered gathered skirt made of 6" squares. I decided to take it apart and make a small quilt top to send back to her to finish and give to one of her chairity projects. The fabric is still good as the dress had been worn only a few times. I found some solid that matched exacttly.
So inspiration can come when you least expect it and often when you are not searching for it. Find something simple to do in the meantime. We do think while sewing - Right?